I have had the same problem since joining NTL and have checked e-billing IS available in my area. I'm also on SACM, so thought I might contact NTL via their online contact page :-
http://www.ntlhome.com/contact/
I entered all the required info, eventually selected the correct dropdown option to report an ebilling problem, and clicked 'send'.
Here is their reply :-
"An error occurred on the server when processing the URL. Please contact the system administrator" !!
Helpful ?
Ho hum, start all over again!